CDMA signal waveform quality display system, method, and program, and storage medium storing the program

ABSTRACT

A signal power coefficient and a noise power coefficient are calculated for each channel, using parameters which have been optimized up to a small error value by an optimizing means, then using the thus-calculated signal power coefficient and noise power coefficient, there are determined a signal power and a noise power for each channel, and the signal power and the noise power thus determined are displayed on one and same display screen channel by channel.

FIELD OF ART

The present invention relates to the display of CDMA signal waveformquality.

BACKGROUND ART

The applicant in the present case has previously proposed such a CDMAsignal waveform quality measuring method as disclosed in Japanese PatentLaid Open No. 173628/1998. FIG. 13 shows an example of power display ofvarious channels as measured by the measuring method disclosed therein.

In FIG. 13, electric power W is plotted along the axis of ordinate,while channels CH are plotted along the axis of abscissa. In the exampleof FIG. 13, Walsh code length is set at “32” to permit connection of32-channel lines, and a state is shown in which channels 0, 1, 3, 5, 7,9, 11, 13 . . . 29, and 31 are generating signals.

According to the conventional method for displaying the result of CDMAsignal waveform quality measurement, a signal power of each channel ismerely displayed and the measurement of noise level is not performed.Particularly, the measurement of noise level is an important parameter,for example, in case of building a base station for portable radiocommunication and making tests.

It is an object of the present invention to provide a CDMA signalwaveform quality display system capable of measuring a noise level foreach channel and displaying the result of the noise level measurement ona power display screen and further capable of displaying both signalpower and noise power of each channel on one and same screen.

DISCLOSURE OF THE INVENTION

According to the present invention as described in claim 1, a CDMAsignal waveform quality display system includes: an orthogonaltransformer for orthogonal transformation of a digital measurementsignal in each channel into a base band signal and correcting a carrierfrequency error; a demodulator for demodulating the measurement signalin each channel corrected by the orthogonal transformer to afforddemodulated data and an amplitude value; an ideal signal generator forgenerating an ideal signal in each channel from the demodulated data,the amplitude value, and estimated parameters; a parameter estimator forestimating various parameters in each channel from the ideal signal ineach channel and the corrected measurement signal in each channel; anoptimizing unit which, using the estimated parameters, performs thecorrection in the orthogonal transformer and the generation of the idealsignal in the ideal signal generator, further performing the processingsin the demodulator and the parameter estimator, and which repeats thecorrection, demodulation, and estimation until the estimated parametersare optimized; a power coefficient calculator which calculates a powercoefficient of the measurement signal in each channel in the optimizedstate in the optimizing unit; a noise power coefficient calculator whichcalculates a noise coefficient channel by channel; and a calculationresult display which determines a signal power and a noise power on thebasis of the power coefficient in each channel calculated in the powercoefficient calculator and the noise power coefficient in each channelcalculated in the noise power coefficient calculator and which displaysthe signal power and noise power on one and same display.

According to the present invention as described in claim 2, a CDMAsignal waveform quality display system includes: a power measuring unitfor measuring a signal component power of a signal to be measured in acertain specific channel to be measured; a noise component powermeasuring unit for measuring a noise component power of the signal to bemeasured in the channel to be measured; and a calculation result displayunit for displaying a graph having a length proportional to the value ofthe signal component power and a graph having a length proportional tothe value of the noise component power in such a manner that in alongitudinal direction of one of the graphs there is disposed the othergraph.

The present invention as described in claim 3, is a CDMA signal waveformquality display system according to claim 2, wherein in the case wherethe channel to be measured is free of the signal component power, thecalculation result display unit displays the graph having a lengthproportional to the value of the noise component power.

The present invention as described in claim 4, is a CDMA signal waveformquality display system according to claim 2 or claim 3, wherein thecalculation result display unit causes a marker to be displayed on adisplay surface and displays the value of the signal component power andof the noise component power in a position indicated by the marker.

The present invention as described in claim 5, is a CDMA signal waveformquality display system according to claim 2, wherein the calculationresult display unit displays the graphs in such an arranged state of thegraphs as avoids overlapping of the graphs, the graphs each having awidth corresponding to a band width which is determined by a diffusioncode length corresponding to the channel to be measured.

The present invention as described in claim 6, is a CDMA signal waveformquality display system according to claim 5, wherein the calculationresult display unit displays the graphs in such a state as the graphsare arranged in accordance with Paley order to avoid overlapping of thegraphs.

According to the present invention as described in claim 7, a CDMAsignal waveform quality display method includes: an orthogonaltransformation step for orthogonal transformation of a digitalmeasurement signal in each channel into a base band signal andcorrecting a carrier frequency error; a demodulating step fordemodulating the measurement signal in each channel corrected by theorthogonal transformation step to afford demodulated data and anamplitude value; an ideal signal generating step for generating an idealsignal in each channel from the demodulated data, the amplitude value,and estimated parameters; a parameter estimating step for estimatingvarious parameters in each channel from the ideal signal in each channeland the corrected measurement signal in each channel; an optimizing stepwhich, using the estimated parameters, performs the correction in theorthogonal transformation step and the generation of the ideal signal inthe ideal signal generating step, further performing the processings inthe demodulating step and the parameter estimating step, and whichrepeats the correction, demodulation, and estimation until the estimatedparameters are optimized; a power coefficient calculating step whichcalculates a power coefficient of the measurement signal in each channelin the optimized state in the optimizing step; a noise power coefficientcalculating step which calculates a noise coefficient channel bychannel; and a calculation result display step which determines a signalpower and a noise power on the basis of the power coefficient in eachchannel calculated in the power coefficient calculating step and thenoise power coefficient in each channel calculated in the noise powercoefficient calculating step and which displays the signal power andnoise power on one and same display.

According to the present invention as described in claim 8, a CDMAsignal waveform quality display method includes: a power measuring stepfor measuring a signal component power of a signal to be measured in acertain specific channel to be measured; a noise component powermeasuring step for measuring a noise component power of the signal to bemeasured in the channel to be measured; and a calculation result displaystep for displaying a graph having a length proportional to the value ofthe signal component power and a graph having a length proportional tothe value of the noise component power in such a manner that in alongitudinal direction of one of the graphs there is disposed the othergraph.

The present invention as described in claim 9, is a program ofinstructions for execution by the computer to perform a CDMA signalwaveform quality display processing, the CDMA signal waveform qualitydisplay processing including: an orthogonal transformation process fororthogonal transformation of a digital measurement signal in eachchannel into a base band signal and correcting a carrier frequencyerror; a demodulating process for demodulating the measurement signal ineach channel corrected by the orthogonal transformation process toafford demodulated data and an amplitude value; an ideal signalgenerating process for generating an ideal signal in each channel fromthe demodulated data, the amplitude value, and estimated parameters; aparameter estimating process for estimating various parameters in eachchannel from the ideal signal in each channel and the correctedmeasurement signal in each channel; an optimizing process which, usingthe estimated parameters, performs the correction in the orthogonaltransformation process and the generation of the ideal signal in theideal signal generating process, further performing the processings inthe demodulating process and the parameter estimating process, and whichrepeats the correction, demodulation, and estimation until the estimatedparameters are optimized; a power coefficient calculating process whichcalculates a power coefficient of the measurement signal in each channelin the optimized state in the optimizing process; a noise powercoefficient calculating process which calculates a noise coefficientchannel by channel; and a calculation result display process whichdetermines a signal power and a noise power on the basis of the powercoefficient in each channel calculated in the power coefficientcalculating process and the noise power coefficient in each channelcalculated in the noise power coefficient calculating process and whichdisplays the signal power and noise power on one and same display.

The present invention as described in claim 10, is a program ofinstructions for execution by the computer to perform a CDMA signalwaveform quality display processing, the CDMA signal waveform qualitydisplay processing including: a power measuring process for measuring asignal component power of a signal to be measured in a certain specificchannel to be measured; a noise component power measuring process formeasuring a noise component power of the signal to be measured in thechannel to be measured; and a calculation result display process fordisplaying a graph having a length proportional to the value of thesignal component power and a graph having a length proportional to thevalue of the noise component power in such a manner that in alongitudinal direction of one of the graphs there is disposed the othergraph.

The present invention as described in claim 11, is a computer-readablemedium having a program of instructions for execution by the computer toperform a CDMA signal waveform quality display processing, the CDMAsignal waveform quality display processing including: an orthogonaltransformation process for orthogonal transformation of a digitalmeasurement signal in each channel into a base band signal andcorrecting a carrier frequency error; a demodulating process fordemodulating the measurement signal in each channel corrected by theorthogonal transformation process to afford demodulated data and anamplitude value; an ideal signal generating process for generating anideal signal in each channel from the demodulated data, the amplitudevalue, and estimated parameters; a parameter estimating process forestimating various parameters in each channel from the ideal signal ineach channel and the corrected measurement signal in each channel; anoptimizing process which, using the estimated parameters, performs thecorrection in the orthogonal transformation process and the generationof the ideal signal in the ideal signal generating process, furtherperforming the processings in the demodulating process and the parameterestimating process, and which repeats the correction, demodulation, andestimation until the estimated parameters are optimized; a powercoefficient calculating process which calculates a power coefficient ofthe measurement signal in each channel in the optimized state in theoptimizing process; a noise power coefficient calculating process whichcalculates a noise coefficient channel by channel; and a calculationresult display process which determines a signal power and a noise poweron the basis of the power coefficient in each channel calculated in thepower coefficient calculating process and the noise power coefficient ineach channel calculated in the noise power coefficient calculatingprocess and which displays the signal power and noise power on one andsame display.

The present invention as described in claim 12, is a computer-readablemedium having a program of instructions for execution by the computer toperform a CDMA signal waveform quality display processing, the CDMAsignal waveform quality display processing including: a power measuringprocess for measuring a signal component power of a signal to bemeasured in a certain specific channel to be measured; a noise componentpower measuring process for measuring a noise component power of thesignal to be measured in the channel to be measured; and a calculationresult display process for displaying a graph having a lengthproportional to the value of the signal component power and a graphhaving a length proportional to the value of the noise component powerin such a manner that in a longitudinal direction of one of the graphsthere is disposed the other graph.

According to the present invention, since not only a signal power ofeach channel but also a noise power of each channel in CDMA signal isdisplayed on the same screen, it is possible to know a signal-to-noiseratio (S/N) easily. There accrues an advantage that it is possible toprovide a CDMA signal waveform quality measuring system convenient foruse.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing the construction of a CDMA signalwaveform quality display system according to a first embodiment of thepresent invention;

FIG. 2 is a diagram showing an example of an arithmetic expression;

FIG. 3 is a diagram showing an example of display;

FIG. 4 is a block diagram showing the construction of a CDMA signalwaveform quality display system according to a second embodiment of thepresent invention;

FIG. 5 is a flow chart showing the operation of a diffusion code lengthsetting updating means 34A, that of a diffusion code number settingupdating means 34B, and further showing in what state arithmeticprocessings are performed in various components;

FIG. 6 is a diagram showing an example of display;

FIG. 7 is a diagram showing diffusion code numbers;

FIG. 8 is a diagram showing an ordinary order and Paley order in case ofWalsh code length being L=8;

FIG. 9 is a diagram showing an ordinary order and Paley order in case ofWalsh code length being L=4;

FIG. 10 is a diagram showing a layout of graphs arranged in Paley order;

FIG. 11 is a diagram showing a layout of graphs arranged in an ordinaryorder;

FIG. 12 is a diagram showing a state in which diffusion code numbers indiffusion code length L=0 has been re-arranged in accordance with Paleyorder; and

FIG. 13 is a diagram showing an example of an power display of variouschannels in the prior art.

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiments of the present invention will be described hereinunder withreference to the accompanying drawings.

First Embodiment

In FIG. 1, a frequency-diffused, multi-channel CDMA signal from a basestation is inputted through an input terminal 11 and is converted to anintermediate frequency signal by means of a down converter 12. Theintermediate frequency signal is amplified by an amplifier 13, then isband-limited by a filter 14, and is thereafter converted to a digitalsignal by an A/D converter 15. The digital intermediate frequency signalfrom the A/D converter 15 is converted to a base band signal by anorthogonal transformer 17 which includes a complementary filter,affording a base band measurement signal Z(k).

The base band measurement signal Z(k) is inverse-diffused in ademodulator 25 with a diffusion code (Walsh code) provided from adiffusion code generator 20 and bit data is demodulated for eachchannel. At the same time, amplitude a′i (i is channel number) of eachchannel is detected.

In an ideal signal generator 26, an ideal signal Ri (i is channelnumber) is produced on the basis of both bit data provided from thediffulator 25 and diffusion code PN (Walsh code) provided from thediffusion code generator 20. Further, in accordance with the idealsignal Ri, the following expressions are calculated to generatecorrection data Ai(k), Bi(k), Ci(k), Ii(k), and Hi(k):

$\begin{matrix}{{A_{i}(k)} = {a_{i}^{\prime} \cdot \left\lbrack {\sum\limits_{m = {- M}}^{M}{{a(m)} \cdot {R_{i}\left( {k - m} \right)}}} \right\rbrack \cdot {\mathbb{e}}^{j\;\theta_{i}^{\prime}}}} & (1) \\{{B_{i}(k)} = {\begin{Bmatrix}{{2\;{a_{i}^{\prime} \cdot \left\lbrack {\sum\limits_{m = {- M}}^{M}{{a(m)} \cdot {R_{i}\left( {k - m} \right)}}} \right\rbrack \cdot \tau_{i}^{\prime}}} +} \\{a_{i}^{\prime} \cdot \left\lbrack {\sum\limits_{m = {- M}}^{M}{{b(m)} \cdot {R_{i}\left( {k - m} \right)}}} \right\rbrack}\end{Bmatrix} \cdot {\mathbb{e}}^{j\;\theta_{i}^{\prime}}}} & (2) \\{{C_{i}(k)} = {\begin{Bmatrix}{{a_{i}^{\prime} \cdot \left\lbrack {\sum\limits_{m = {- M}}^{M}{{a(m)} \cdot {R_{i}\left( {k - m} \right)}}} \right\rbrack \cdot \tau_{i}^{\prime\; 2}} +} \\{{a_{i}^{\prime} \cdot \left\lbrack {\sum\limits_{m = {- M}}^{M}{{b(m)} \cdot {R_{i}\left( {k - m} \right)}}} \right\rbrack \cdot \tau_{i}^{\prime}} +} \\{a_{i}^{\prime} \cdot \left\lbrack {\sum\limits_{m = {- M}}^{M}{{c(m)} \cdot {R_{i}\left( {k - m} \right)}}} \right\rbrack}\end{Bmatrix} \cdot {\mathbb{e}}^{j\;\theta_{i}^{\prime}}}} & (3) \\{{I_{i}(k)} = {\begin{Bmatrix}{{\left\lbrack {\sum\limits_{m = {- M}}^{M}{{a(m)} \cdot {R_{i}\left( {k - m} \right)}}} \right\rbrack \cdot \tau_{i}^{\prime\; 2}} +} \\{{\left\lbrack {\sum\limits_{m = {- M}}^{M}{{b(m)} \cdot {R_{i}\left( {k - m} \right)}}} \right\rbrack \cdot \tau_{i}^{\prime}} +} \\\left\lbrack {\sum\limits_{m = {- M}}^{M}{{c(m)} \cdot {R_{i}\left( {k - m} \right)}}} \right\rbrack\end{Bmatrix} \cdot {\mathbb{e}}^{j\;\theta_{i}^{\prime}}}} & (4) \\{{H_{i}(k)} = {\begin{Bmatrix}{{2 \cdot \left\lbrack {\sum\limits_{m = {- M}}^{M}{{a(m)} \cdot {R_{i}\left( {k - m} \right)}}} \right\rbrack \cdot \tau_{i}^{\prime\;}} +} \\{\mspace{31mu}\left\lbrack {\sum\limits_{m = {- M}}^{M}{{b(m)} \cdot {R_{i}\left( {k - m} \right)}}} \right\rbrack}\end{Bmatrix} \cdot {\mathbb{e}}^{j\;\theta_{i}^{\prime}}}} & (5)\end{matrix}$

The ideal signal Ri is obtained in the following manner. Demodulated bitdata of each channel i provided from the demodulator 25 areinverse-diffused with I- and Q-side diffusion codes (Walsh codes)provided from the diffusion code generator 20, then chips “0” and “1” inthe thus inversion-diffused I- and Q-side chip rows are converted to+√{square root over ( )}2 and −{square root over ( )}2, respectively toafford I and Q signals of QPSK signal with an amplitude of 1. That is,using the ideal signal Ri(k−m) with a normalized amplitude and theamplitude a′i from the demodulator 25, there are calculated auxiliarydata Ai(k), Bi(k), Ci(k), Ii(k), and Hi(k).

The auxiliary data Ai(k), Bi(k), Ci(k), Ii(k), and Hi(k) and themeasurement signal Z(k) are inputted to a parameter estimator 27, inwhich simultaneous equations shown in FIG. 2 are solved and estimatevalues Δai, Δτi, Δθi, and Δω are obtained as solutions thereof. Usingthese estimate values, the correction parameters so far used a′i, τ′i,θ′i, and ω′ are updated as follows in a transformer 28:ω′←ω′+Δωa′i←a′i+Δaiτ′i←τ′i+Δτiθ′i←θ′i+Δθi  (6)

Then, using the thus-corrected parameters a′i, τ′i, θ′i, and ω′,correction is made for the measurement signal Z(k) and thethus-corrected measurement signal Z(k) is again subjected to theprocessings in the demodulator 25, the ideal signal/auxiliary datagenerator 26, the parameter estimator 27, and the transformer 28. Theseprocessings are carried out until the estimate values Δai, Δτi, Δθi, andΔω are optimized, that is, until reaching zero or near zero, or untilthere occurs no change of value ever with repetition. By this optimizingstep, correction is made not only for the measurement signal Z(k) butalso for the ideal signal Ri.

Therefore, an optimizing means 22 is constituted by the orthogonaltransformer 17 which includes a complementary filter, the demodulator25, the ideal signal generator 26, the parameter estimator 27, and thetransformers 28 and 29.

Correction for the measurement signal Z(k) is made as follows relativeto Z(k) of the last time:Z(k)←Z(t−τ′0)(1/a′0)exp [−j(ω′(t−τ′0)+θ′0)]  (7)

As initial values are set a′0=1, τ′0=0, θ′0=0, and ω′=0, and each timeestimate values are obtained in the parameter estimator 27, theexpression (7) is calculated with respect to new a′i, τ′i, θ′i, and ω′.That is, this calculation for correction is made for the signal inputtedto the orthogonal transformer/complementary filter 17, i.e., the outputof the A/D converter 15.

The calculation for correction may be performed for the measurementsignal Z(k) after conversion to the base band. However, this baseband-converted signal is a signal after having passed the complementaryfiler (the same pass band width as the band width of the input signal).If there is a gross frequency error, this filter processing may resultin that a portion of the signal is removed, that is, the measurementsignal to be used in parameter estimation, etc., is chipped. Therefore,the result of the frequency estimation is corrected at a stage whichprecedes the complementary filter. But the correction may be made forthe measurement signal after conversion to the base band, provided thereis used a low pass filter of a sufficiently wide band without using thecomplementary filter in the orthogonal transformer/complementary filter17.

The correction parameters a′i, τ′i, and θ′i are subjected to thefollowing conversion in the transformer 29:a″i=a′i/a′0τ″i=τ′i−τ′0θ″i=θ′i−θ′0 provided i≠0  (8)

As to the measurement signal Z(k), since the parameters of the 0^(th)channel are corrected by the expression (7), the parameters forcorrecting the 0^(th) ideal signal R₀ are normalized into the followingvalues:

a″0=1

τ″0=0

θ″0=0

The parameters for the ideal signal Ri of channels other than the 0^(th)channel are corrected by 0^(th) parameters as in the expression (8).

That is, in the first repetition in the foregoing optimization step,correction for the measurement signal Z(k) is made using the correctionparameters of the 0^(th) channel and therefore, as correction parametersused in the auxiliary data generator 26, there is used the expression(8) normalized by the parameters of the 0^(th) channel, i.e., atransformed output of the transformer 29. More particularly, thecalculations of the expressions (1) to (5) are performed usingparameters which are conceivable in the expression (8) to determineauxiliary data Ai(k), Bi(k), Ci(k), Ii(k), and Hi(k). In thesecalculations for determining auxiliary data there are used bit data andamplitude a′i, the bit data being obtained as a result of demodulatingZ(k) in the demodulator 25 after correction by the expression (7).

Thus, both corrections described above are performed every time estimatevalues are obtained from the parameter estimator 27, and the estimationof parameters is again repeated until optimization of the estimatevalues, whereupon a power coefficient ρi is calculated and determined asfollows in a power coefficient calculator 31, using measurement signalZ(k) and diffusion code (Walsh code) obtained at that instant:

$\begin{matrix}{\rho_{i} = \frac{\sum\limits_{j = 1}^{N}{{\sum\limits_{k = 1}^{64}{Z_{j,k}R_{i,j,k}^{*}}}}^{2}}{\left\{ {\sum\limits_{k = 1}^{64}{R_{i,j,k}}^{2}} \right\}\left\{ {\sum\limits_{j = 1}^{N}{\sum\limits_{k = 1}^{64}{Z_{j,k}}^{2}}} \right\}}} & (9)\end{matrix}$The expression (9) is the same as the expression defined by the CDMAsignal measurement standard and used in the prior art.

The following calculation is performed in a transformer 32:a^=a′Δτ^i=τ′i−τ′0Δθ^i=θ′i−θ′0Δω^=ω′  (10)

The parameters a^, Δτ^i, Δθ^i, Δω^, τ^0, and the power coefficient ρiobtained in the power coefficient calculator 31 are displayed on acalculation result display 33.

As described above, the measurement signal Z(k) and the ideal signal Riare corrected using estimated parameters, and the estimation ofparameters is again performed using both corrected signals untiloptimization of the estimated parameters. Since all the parameters areused in this optimization, all the parameters are optimized, and afterthe optimization, the power coefficient ρi is determined using themeasurement signal, so that the power coefficient ρi can be obtainedwith a high accuracy. Other parameters are also determined with a highaccuracy because the measurement signal is included in the optimizationloop.

In the CDMA signal waveform quality display system of the firstembodiment, a noise coefficient calculator 31A is provided in the powercoefficient calculator 31 to calculate a noise coefficient ρ_(Ni) ofeach channel. Further, a noise power display 33A is provided in thecalculation result display 33, and the noise coefficient ρ_(Ni) of eachchannel calculated in the noise power coefficient calculator 31A isinputted to the noise power display 33A, allowing a noise power to becalculated.

Signal power and noise power of each channel are calculated in thefollowing manner.Signal power W _(s)=10.0×log₁₀(ρi)

The value of ρi is obtained in the foregoing expression (9). Although inthe expression (9) there is shown an example in which Walsh code lengthis fixed to 64, Walsh length actually takes the values of 4, 8, 16, 32,64, 128, and 256 for various channels.

Noise power coefficient ρ_(Ni) (code Domain Error) is calculated asfollows using Z_(j)·k and Ri·j·k in the expression (9).

The sum of channels in the ideal signal Ri is subtracted from themeasurement signal Z to obtain an error signal N, and a powercoefficient is determined as follows with respect to the error signal N:

$\begin{matrix}{N_{i \cdot k} = {Z_{j \cdot k} - {\sum\limits_{i}^{L - 1}R_{i \cdot j \cdot k}}}} \\{\rho_{N\; i} = \frac{\sum\limits_{j = 1}^{({M/L})}{{\sum\limits_{k = 1}^{L}{N_{j \cdot k} \times R_{i \cdot j \cdot k}^{*}}}}^{2}}{\left\{ {\sum\limits_{k = 1}^{L}{R_{i \cdot j \cdot k}}^{2}} \right\}\left\{ {\sum\limits_{j = 1}^{({M/L})}{\cdot {\sum\limits_{k = 1}^{L}{Z_{j \cdot k}}^{2}}}} \right\}}}\end{matrix}$

A noise power W_(N) of i channel is calculated as follows:W _(N)=10.0×log₁₀(ρ_(Ni))

The result of the calculation is stored in a memory in a pair with thesignal power W_(S) channel by channel. The values of signal power W_(S)and noise power W_(N) in each channel are graphed by a graph plottingmeans (included in the calculation result display 33) and written as agraph in an image memory. The values of signal power W_(S) and noisepower W_(N) in all the channels are all stored in the image memory,whereby the states of all the channels are displayed on the display.

FIG. 3 shows an example of the plotting. In the same figure, hatchedportions (graphs) with solid lines represent signal powers W_(S) of thechannels, while dotted line portions (graphs) represent noise powersW_(N) of the channels. As shown in the figure, signal-free channels arealso measured for noise power and the results are displayed. The height(length) of each graph represents the signal power W_(S) and noise powerW_(N) of each channel. The graphs of noise power W_(N) underlie vertical(longitudinal) extension lines of the graphs of signal power W_(S).

In the channels 2, 4, 6, 8, 10, 12, . . . , 30 there is no signal powerW_(S) and only the graphs of noise power W_(N) are shown.

The solid line and dotted line portions in FIG. 3 may actually berepresented in different line colors in the case of a color display tomake distinction in display between signal power W_(S) and noise powerW_(N).

The symbol M in the figure stands for a marker. By moving the marker Mto the portion whose measured value is to be known, it is possible tolet the measured value at that position be displayed in a numericalvalue display column 34. In the state of display shown in FIG. 3, thechannel indicated by the marker M is “5”, Walsh code length is 32, noisepower CDE is −55.22 dBm, and signal power POWER is −32.29 dBm.

Second Embodiment

This second embodiment is different from the first embodiment in thatbar graphs are arranged and displayed in accordance with Paley order.

FIG. 4 is a block diagram showing the construction of a CDMA signalwaveform quality display system according to the second embodiment ofthe present invention. In this embodiment the same portions as in thefirst embodiment are identified by like reference numerals andexplanations thereof will be omitted.

The CDMA signal waveform quality display system of this secondembodiment is further provided, in addition to the components describedin the first embodiment, with a diffusion code length setting updatingmeans 34A, a diffusion code number setting updating means 34B, a settingmeans 35, a memory 33A′, a graphing means 33B, and an image memory 33C.

In accordance with diffusion code length L and diffusion code number iproduced in the diffusion code length setting updating means 34A and thediffusion code number setting updating means 34B, the diffusion codegenerator 20 generates a diffusion code PN corresponding to all thechannels for each diffusion code length L, and with this diffusion codePN the demodulator 25 demodulates the signal of each channel at eachdiffusion code length.

In this second embodiment there is added a construction in which theideal signal generator 26 generates an ideal signal Ri from the dataobtained by demodulation, and various parameters Δai, Δτi, Δθi, and Δωare produced in the parameter estimator 27 in accordance with the idealsignal Ri, then those parameters are fed back to the orthogonaltransformer 17 for optimization processing, to afford a signal Z(k) withfew errors.

The signal Z(k) with few errors is inputted to the power coefficientcalculator 31, which in turn calculates power coefficients ρi of thechannels. The power coefficients ρi thus calculated in the powercoefficient calculator 31 and the parameters ^ai·L, Δ^τi·L, Δ^θi·L, Δ^ω,τ0′ outputted from the transformer 32 are stored in the memory 33A′ inaccordance with respective diffusion code lengths and diffusion codenumbers.

A setting means 35 sets a to-be-displayed channel (the channel of asignal transmitted by a communication device being measured) among allthe channels stored in the memory 33A′ and reads the power coefficientρi and parameters of the channel thus set. In this example, therefore,electric power of the channel set in the setting means 35 is displayedon the calculation result display 33.

FIG. 5 shows the operation of the diffusion code length setting updatingmeans 34A and that of the diffusion code number setting updating means34B and also shows in what state arithmetic processings are performed invarious components.

In step SP1, Walsh code length as diffusion code length is initializedat L=4, then in step SP2, Walsh code (corresponding to channel number)as diffusion code number is set at i=0.

In step SP3, an ideal signal Ri·L based on Walsh code length L=4 andWalsh code i=0 is produced in the ideal signal generator 26.

In step SP4, parameters are estimated in the parameter estimator 27 inaccordance with the ideal signal Ri·L and are then fed back to theorthogonal transformer 17 for optimization processing. Then, the powercoefficient ρi·L is calculated on the basis of the measurement signalZ(k) after optimization processing and the diffusion code produced inthe diffusion code generator 20.

In step SP5, the power coefficient ρi·L calculated in step SP4 and otherparameters ^ai·L, Δ^τi·L, Δ^θi·L, Δ^ω, τ0′ are stored in the memory33A′. At this time, the noise coefficient ρNi is also stored in thememory 33A′.

In step SP6, the value of Walsh code i is updated as i+1, then in stepSP7, the value of Walsh code length L and that of Walsh code i arecompared with each other. If both disagree, the processing flow returnsto step SP3. That is, in case of Walsh code length L=4, i=4 results fromexecuting the steps SP3-SP7 four times, and the flow advances to stepSP8.

In step SP8, the value L of Walsh code length is doubled for updating toL=8. In step SP9, a check is made to see if the value L of Walsh codelength has become larger than the maximum value 128. If the value L ofWalsh code length has become larger than the maximum value 128, the flowreturns to step SP2.

In step SP2, initialization is made again to i=0 and the routine ofsteps SP3-SP7 is executed. With L=8, the routine of steps SP3-SP7 isexecuted eight times. In this eight-time execution, power coefficientsρi·L, noise coefficients ρNi, and parameters ^ai, Δ^τi, Δ^θi, Δ^ω, τ0′for eight channels of 0-7 defined for Walsh code length of L=8 arecalculated and are stored in the memory 33A′.

In this way the Walsh code length L is updated in the order of 4, 8, 16,32, 64, and 128, and power coefficient ρi·L, noise coefficient ρNi, andparameters ^ai, Δ^τi, Δ^θi, Δ^ω, τ0′, are stored in the memory 33A′ foreach channels determined by each Walsh code length L.

If it is detected in step SP9 that the value L of Walsh length hasexceeded the maximum value of 128, the processing flow branches to stepSP10.

In step SP10, a power coefficient of each channel is calculated from theWalsh code length as a desired diffusion code length set in the settingmeans 35 and also from an address which depends on the diffusion codenumber (Walsh code number), and a signal power of each channel isdetermined from the power coefficient ρi thus obtained.

Signal power W_(S) can be calculated as follows from the powercoefficient ρi·L:W _(S)=10.0×log₁₀  (ρi·L)

This conversion to electric power can be done in the graphing means 33Bfor example. How to obtain the noise power W_(N) is the same as in thefirst embodiment, and also in this case the graphing means 33B may beutilized.

Data converted to signal power and noise power can be graphed by thegraphing means 33B, but in this example the level of electric power isrepresented in terms of a strip-like display region (bar graph) channelby channel. Therefore, the length in Y-axis direction of the strip-likedisplay region depends on the converted electric power value. In thepresent invention. Moreover, the width (in X-axis direction) of thestrip-like display region is determined correspondingly to the diffusioncode length L.

In determining the said width, the width of the display region ofchannel belonging to L=4 in diffusion code length L is selected to thelargest width W. The width is made corresponding to the value ofdiffusion code length L so that the larger the value of L, the narrowerthe width, like ½ of the width W in L=4 in case of the diffusion codelength L=8, further, ½ width thereof, ¼ (W), in case of L=16, ½ widththereof, ⅛ (W), in case of L=32, . . . By so doing it is possible toclearly display the relation of channel band widths given to thediffusion code lengths.

FIG. 6 shows an example of the display in question. W4 shown in FIG. 6represents a display region given in terms of the diffusion code number“1” in diffusion code length L=4.

W8 represents a display region given in terms of the diffusion codenumber 2 in diffusion code length L=8.

W16 represents a display region given in terms of the diffusion codenumber 6 in diffusion code length L=16.

W32 represents a display region given in terms of diffusion code number23 in diffusion code length L=32.

W64 represents a display region given in terms of diffusion code number60 in diffusion code length L=64.

W128 represents a display region given in terms of diffusion code number0 in diffusion code length L=128.

In FIG. 6, channel number and electric power are plotted along the axisof abscissa and the axis of ordinate, respectively. As shown at W4 inFIG. 6, it is preferable that a noise component graph underlie a signalcomponent graph on an extension line of the length (height) of thelatter graph, as in the first embodiment. This is also the same as theother display regions.

From a read address of power coefficient which is read out of the memory33A′ the graphing means 33B can know the diffusion code length L towhich the read power coefficient ρi belongs. On the basis of the valueof the diffusion code length L it is possible to determine the widths ofthe display regions W4, W8, W16, W32, W64, and W128.

In the graphing means 33B, moreover, colors can be affixed to thedisplay regions W4, W8, W16, W32, W64, and W128 in accordance with thediffusion code number of the power coefficient read from the memory33A′. In the example of FIG. 6, the contour lines of the display regionsW4, W8, W16, W32, W64, and W128 may be colored in black, blue, green,dark blue, yellow, and red, respectively. The thus-colored image dataare stored in the image memory 33C and the thus-stored images aredisplayed on a display result display 33D.

The present invention further proposes that in the graphing means 33Bthe display positions in X-axis direction of the display regions W5-W128be not defined by the diffusion code numbers shown in FIG. 7 but definedin accordance with Paley order.

FIG. 7 shows a relation between Walsh code length and Walsh code. L=4,L=8, L=16, . . . shown in the left column represent Walsh lengths. AtWalsh code length L=4, a predetermined band width ΔF is divided in fourand four channels of 0, 1, 2, and 3 are allocated thereto. The channelnumbers 0, 1, 2, and 3 of the four channels are given in terms of Walshcode numbers 0, 1, 2, and 3. As is seen from FIG. 7, as Walsh codelength becomes larger, the number of employable channels increases in adoubly increasing relation and an employable band width becomes narrowerin decrements of ½. From this relation it will be seen that a shortWalsh code length is allocated to a telephone set which handles a largevolume of data to be transmitted, while a long Walsh code length isallocated to a telephone set which handles a small volume of data. InFIG. 7 Walsh code lengths 64 and 128 are omitted.

According to Paley order, numbers are given in terms of bit numberscorresponding to Walsh code lengths as diffusion codes shown in FIG. 8Aand the arrangement of bits obtained when the numbers are represented inbinary is reversed. The numbers in such a reverse bit order become thenumbers in Paley order.

More specifically, Paley order is as shown in FIG. 8B relative to thearrangement of Walsh codes shown in FIG. 8A. FIG. 9A shows an ordinaryorder of Walsh codes and FIG. 9B shows Paley order.

By defining the position on X axis of each channel in a multiplexedsignal in accordance with Paley order, there accrues an advantage thatthere can be made display without overlapping of display regions as inFIG. 10. It is preferable that signal component and noise component bedisplayed in display regions C1 and C2. This is the same as in the abovedescription taken in connection with FIG. 6.

This is for the following reason. In this type of a communicationdevice, there is established a limitation so as to select channels inwhich diffusion codes are in an orthogonal relation for diminishinginterference between channels. In case of selecting channels inaccordance with the said limitation of channel selection, there arises acondition in which display regions overlap each other in display, as isillustrated in FIG. 11.

More specifically, in the case where there is displayed an electricpower of a signal corresponding to a combination of code number 2 inWalsh code length L=4 and code number 4 in Walsh code length L=8, whichcombination is also a normal combination, the power displaying region C1and C2 overlap each other as in FIG. 11. In this case, the power displayof code number 4 in Walsh code length L=8 is included within the displayregion C2 and it becomes uncertain whether a signal of the channelcorresponding to code number 4 in Walsh code length L=8 is present ornot.

That is, there is a case where only the display region C2 appears to bepresent and there also is a case where signals appear to be present inboth code numbers 4 and 5 of Walsh code length L=8, thus giving rise tothe drawback that the measurement becomes indistinct.

For remedying this drawback the present invention proposes that thedisplay positions on X axis of the display regions W4˜W128 be determinedin accordance with Paley order.

FIG. 10 shows a state in which the overlapped state of both displayregions C1 and C2 in FIG. 11 has been extinguished by making the displayin accordance with Paley order. In case of the diffusion code lengthL=4, Paley order is like 0, 2, 1, 3 in terms of diffusion code numbersas in FIG. 9B. This order of diffusion code numbers 0, 2, 1, 3corresponds to channel numbers 0, 1, 2, 3.

On the other hand, with the diffusion code length L=8, Paley order islike 0, 4, 2, 6, 1, 5, 3, 7 as is apparent from FIG. 8B.

The display region C1 shown in FIG. 11 displays an power of a signalwhich belongs to diffusion code number 4, and therefore, in accordancewith Paley order the power is displayed in the position of channel No. 1in L=8, as shown in FIG. 10.

On the other hand, the display region C2 shown in FIG. 11 displays anelectric power of a signal which belongs to diffusion code number 2 inL=4, and therefore, in accordance with Paley order the power isdisplayed in the position of channel No. 1 in L=4.

As is seen from FIG. 10, the display regions C1 and C2 do not overlapeach other in display. In other words, channels selected in accordancewith channel selecting conditions in a communication device (a portabletelephone set) described previously never overlap in their channelpositions when conversion is made into Paley order.

The reason for this will now be described with reference to FIG. 12.FIG. 12 shows a state in which diffusion code numbers in diffusion codelength L=0 has been re-arranged in accordance with Paley order.

The channel selecting condition in a communication device is as follows:“A channel of a higher hierarchical level than the selected channelshould not be selected.” In this connection, it is apparent that whencode number 1 in L=4 and code number 1 in L=8 are selected, the coderelations are not orthogonal to each other. For example, in the casewhere a channel specified by code number 0 in L=4 is selected, itfollows that channels specified by overlying code numbers 0, 4 in L=8,code numbers 0, 8, 4, 12 in L=16, and code numbers 0, 16, 8, 24, 4, 20,12, 28 in L=32 do not satisfy the selection condition.

Likewise, when there is used a channel specified by code number 6 inL=8, channels specified by overlying code numbers 6, 14 in L=16 and codenumbers 6, 22, 14, 30 in L=32 do not satisfy the channel selectingcondition.

As is apparent from the above description, as to a channel selected inaccordance with the channel selecting condition in a portable telephoneset, if a display position of the channel is specified in accordancewith Paley order, there never occurs a positional overlap in display.

This principle is also applicable to a method of determining a channelto be used in a base station for portable telephone.

The above embodiments can be implemented in the following manner. In acomputer provided with a CPU, a hard disk, and a media (e.g., floppydisk and CD-ROM) reader, the media reader is allowed to read a mediawhich stores programs for implementing the foregoing components and theread data are installed in a hard disk. Even with such a method it ispossible to implement the functions described above.

According to the present invention, as set forth above, since bothsignal power and noise power of each channel in CDMA signal are measuredat a time and the result of the measurement is displayed on one and samescreen, so it is possible to know a signal-to-noise ratio (S/N) at aglance. As a result, for example in case of building a base station forportable telephone and making a shipping inspection or in the event offailure of the base station which is in service, it is possible todetect immediately in which channel noise is occurring. Thus it ispossible to provide a measuring instrument which is convenient for use.

1. A CDMA signal waveform quality display system, comprising: anorthogonal transformer configured to orthogonally transform a digitalmeasurement signal in each channel into a base band signal and tocorrect a carrier frequency error; a demodulator configured todemodulate the measurement signal in each channel corrected by saidorthogonal transformer to afford demodulated data and an amplitudevalue; an ideal signal generator configured to generate an ideal signalin each channel from said demodulated data, said amplitude value, andestimated parameters; a parameter estimator configured to estimatevarious parameters in each channel from said ideal signal in eachchannel and the corrected measurement signal in each channel; anoptimizer configured to, using said estimated parameters, perform thecorrection in said orthogonal transformer and the generation of theideal signal in said ideal signal generator, and to further perform theprocessings in said demodulator and said parameter estimator, theoptimizer being further configured to repeat said correction,demodulation, and estimation until said estimated parameters areoptimized; a power coefficient calculator configured to calculate apower coefficient of the measurement signal in each channel in theoptimized state in said optimizer; a noise power coefficient calculatorconfigured to calculate a noise coefficient channel by channel; and acalculation result display configured to determine a signal power and anoise power on the basis of the power coefficient in each channelcalculated in said power coefficient calculator and the noise powercoefficient in each channel calculated in said noise power coefficientcalculator and to display said signal power and noise power on a singledisplay.
 2. A CDMA signal waveform quality display system, comprising: apower measurer configured to measure a signal component power of asignal to be measured in a specific channel to be measured; a noisecomponent power measurer configured to measure a noise component powerof the signal to be measured in the channel to be measured; and acalculation result display configured to display a graph having a lengthproportional to the value of said signal component power and a graphhaving a length proportional to the value of said noise component powerin such a manner that in a length direction of one of said graphs thereis disposed the other graph, said graphs each having a widthcorresponding to a band width of the channel to be measured, whereinsaid calculation result display is further configured to display saidgraphs in an arrangement of graphs that avoids overlapping of thegraphs, said band width being determined by a diffusion code lengthcorresponding to the channel to be measured.
 3. A CDMA signal waveformquality display system according to claim 2, wherein said calculationresult display is further configured to display said graphs in anarrangement in accordance with a Paley order to avoid overlapping of thegraphs.
 4. A CDMA signal waveform quality display method, comprising:orthogonally transforming a digital measurement signal in each channelinto a base band signal and correcting a carrier frequency error;demodulating the measurement signal in each channel corrected by theorthogonal transforming to afford demodulated data and an amplitudevalue; generating an ideal signal in each channel from the demodulateddata, the amplitude value, and estimated parameters; estimating variousparameters in each channel from the ideal signal in each channel and thecorrected measurement signal in each channel; optimizing, using theestimated parameters, the correction in the orthogonal transforming andthe generation of the ideal signal in the ideal signal generating, andthe processings in the demodulating and the parameter estimating, andrepeating the correction, demodulation, and estimation until theestimated parameters are optimized; calculating a power coefficient ofthe measurement signal in each channel in the optimized state in theoptimizing; calculating a noise power coefficient channel by channel;and displaying a calculation result which determines a signal power anda noise power on the basis of the power coefficient in each channelcalculated in the power coefficient calculating and the noise powercoefficient in each channel calculated in the noise power coefficientcalculating and which displays the signal power and the noise power on asingle display.
 5. A computer readable medium that stores a computerprogram for execution by a computer to perform a CDMA signal waveformquality display, the computer readable medium comprising: an orthogonaltransformation code segment for orthogonally transforming a digitalmeasurement signal in each channel into a base band signal andcorrecting a carrier frequency error; a demodulating code segment fordemodulating the measurement signal in each channel corrected by theorthogonal transformation to afford demodulated data and a amplitudevalue; an ideal signal generating code segment for generating an idealsignal in each channel from the demodulated data, the amplitude value,and estimated parameters; a parameter estimating code segment forestimating various parameters in each channel from the ideal signal ineach channel and the corrected measurement signal in each channel; anoptimizing code segment which, using the estimated parameters, correctsthe orthogonal transformation and the ideal signal generating and,further performs the demodulating and the parameter estimating, andwhich repeats the correction, demodulation, and estimation until theestimated parameters achieve an optimized state; a power coefficientcalculating code segment which calculates a power coefficient of themeasurement signal in each channel in the optimized state; a noise powercoefficient calculating code segment which calculates a noisecoefficient channel by channel; and a calculation result display codesegment which determines a signal power and a noise power on the basisof the power coefficient in each channel calculated in the powercoefficient calculating and the noise power coefficient in each channelcalculated in the noise power coefficient calculating, and which displaythe signal power and noise power on a single display.
 6. A computerreadable medium that stores a computer program for execution by acomputer to perform a CDMA signal waveform quality display, the computerreadable medium comprising: a power measuring code segment for measuringa signal component power of a signal to be measured in a specificchannel to be measured; a noise component power measuring code segmentfor measuring a noise component power of the signal to be measured inthe channel to measured; and a calculation result display code segmentfor displaying a graph having a length proportional to the value of thesignal component power and a graph having a length proportional to thevalue of the noise component power in such a manner that in a lengthdirection of one of the graphs there is disposed the other graph.
 7. Acomputer-readable medium having a program of instructions for executionby the computer to perform a CDMA signal waveform quality displayprocessing, said CDMA signal waveform quality display processingcomprising: an orthogonal transformation process for orthogonaltransformation of a digital measurement signal in each channel into abase band signal and correcting a carrier frequency error; ademodulating process for demodulating the measurement signal in eachchannel corrected by said orthogonal transformation process to afforddemodulated data and an amplitude value; an ideal signal generatingprocess for generating an ideal signal in each channel from saiddemodulated data, said amplitude value, and estimated parameters; aparameter estimating process for estimating various parameters in eachchannel from said ideal signal in each channel and the correctedmeasurement signal in each channel; an optimizing process which, usingsaid estimated parameters, performs the correction in said orthogonaltransformation process and the generation of the ideal signal in saidideal signal generating process, further performing the processings insaid demodulating process and said parameter estimating process, andwhich repeats said correction, demodulation, and estimation until saidestimated parameters are optimized; a power coefficient calculatingprocess which calculates a power coefficient of the measurement signalin each channel in the optimized state in said optimizing process; anoise power coefficient calculating process which calculates a noisecoefficient channel by channel; and a calculation result display processwhich determines a signal power and a noise power on the basis of thepower coefficient in each channel calculated in said power coefficientcalculating process and the noise power coefficient in each channelcalculated in said noise power coefficient calculating process and whichdisplay said signal power and noise power on one and same display.
 8. ACDMA signal waveform quality display system, comprising: an orthogonaltransformer for orthogonal transformation of a digital measurementsignal in each channel into a base band signal and correcting a carrierfrequency error; a demodulator for demodulating the measurement signalin each channel corrected by said orthogonal transformer to afforddemodulated data and an amplitude value; an ideal signal generator forgenerating an ideal signal in each channel from said demodulated data,said amplitude value, and estimated parameters; a parameter estimatorfor estimating various parameters in each channel from said ideal signalin each channel and the corrected measurement signal in each channel; anoptimizer which, using said estimated parameters, performs thecorrection in said orthogonal transformer and the generation of theideal signal in said ideal signal generator, further performing theprocessings in said demodulator and said parameter estimator, and whichrepeats said correction, demodulation, and estimation until saidestimated parameters are optimized; a power coefficient calculator whichcalculates a power coefficient of the measurement signal in each channelin the optimized state in said optimizing element, a noise powercoefficient calculator which calculates a noise coefficient channel bychannel; and a calculation result display which determines a signalpower and a noise power on the basis of the power coefficient in eachchannel calculated in said power coefficient calculator and the noisepower coefficient in each channel calculated in said noise powercoefficient calculator and which displays said signal power and noisepower on a single display.
 9. A CDMA signal waveform quality displaysystem, comprising: a power measurer configured to measure a signalcomponent power of a signal to be measured in a specific channel to bemeasured; a noise component power measurer configured to measure a noisecomponent power of the signal to be measured in the channel to bemeasured; a calculation result display configured to display a graphhaving a length proportional to the value of said signal component powerand a graph having a length proportional to the value of said noisecomponent power in such a manner that in a length direction of one ofsaid graphs there is disposed the other graph, said graphs each having awidth corresponding to a band width of the channel to be measured,wherein said calculation result display causes a marker to be displayedon a display surface and displays the value of said signal componentpower and of said noise component power in a position indicated by saidmarker, and wherein said calculation result display is furtherconfigured to display said graphs in an arrangement of graphs thatavoids overlapping of the graphs, said band width being determined by adiffusion code length corresponding to the channel to be measured.
 10. ACDMA signal waveform quality display system, comprising: a powermeasurer configured to measure a signal component power of a signal tobe measured in a specific channel to be measured; a noise componentpower measurer configured to measure a noise component power of thesignal to be measured in the channel to be measured; and a calculationresult display configured to display a graph having a lengthproportional to the value of said signal component power and a graphhaving a length proportional to the value of said noise component powerin such a manner that in a length direction of one of said graphs thereis disposed the other graph, said graphs each having a widthcorresponding to a band width of the channel to be measured, whereinwhen said channel to be measured is free of said signal component power,said calculation result display being further configured to display thegraph having a length proportional to the value of said noise componentpower; wherein said calculation result display is further configured tocause a marker to be displayed on a display surface and to display thevalue of said signal component power and of said noise component powerin a position indicated by said marker; and wherein said calculationresult display is further configured to display said graphs in anarrangement in accordance with a Paley order to avoid overlapping of thegraphs.